On 23/10/2018 14:07, Aleksandar Markovic wrote:
> From: Aleksandar Rikalo <arik...@wavecomp.com>
>
> Implement support for translation of system call statx(). The
> implementation includes invoking other (more mature) syscalls
> (from the same 'stat' family) on the host side. This way,
> problems of availability of statx() on the host side are
> avoided.
>
> Signed-off-by: Aleksandar Rikalo <arik...@wavecomp.com>
> Signed-off-by: Stefan Markovic <smarko...@wavecomp.com>
> Signed-off-by: Aleksandar Markovic <amarko...@wavecomp.com>
> ---
> linux-user/syscall.c | 129
> +++++++++++++++++++++++++++++++++++++++++++++-
> linux-user/syscall_defs.h | 38 ++++++++++++++
> 2 files changed, 166 insertions(+), 1 deletion(-)
>
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index d2cc971..8b01ab0 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -6710,7 +6710,8 @@ static abi_long do_syscall1(void *cpu_env, int num,
> abi_long arg1,
> abi_long ret;
> #if defined(TARGET_NR_stat) || defined(TARGET_NR_stat64) \
> || defined(TARGET_NR_lstat) || defined(TARGET_NR_lstat64) \
> - || defined(TARGET_NR_fstat) || defined(TARGET_NR_fstat64)
> + || defined(TARGET_NR_fstat) || defined(TARGET_NR_fstat64) \
> + || defined(TARGET_NR_statx)
> struct stat st;
> #endif
> #if defined(TARGET_NR_statfs) || defined(TARGET_NR_statfs64) \
> @@ -9635,6 +9636,132 @@ static abi_long do_syscall1(void *cpu_env, int num,
> abi_long arg1,
> ret = host_to_target_stat64(cpu_env, arg3, &st);
> return ret;
> #endif
> +#if defined(TARGET_NR_statx)
> + case TARGET_NR_statx:
> + {
> + struct target_statx *target_stx;
> + int dirfd = tswap32(arg1);
> + int flags = tswap32(arg3);
> +
Normally arg1, arg3 are already in the host byte order (like arg2 below)
> + p = lock_user_string(arg2);
> + if (p == NULL) {
> + return -TARGET_EFAULT;
> + }
> +#if defined(__NR_statx)
> + {
> + /*
> + * It is assumed that struct statx is arhitecture independent
> + */
> + struct target_statx host_stx;
if it is host_statx, the structure to use is statx, not target_statx.
> + int mask = tswap32(arg4);
no tswap32() needed
> +
> + ret = get_errno(syscall(__NR_statx, dirfd, p, flags, mask,
> + &host_stx));
> + if (!is_error(ret)) {
> + unlock_user(p, arg2, 0);
> + if (!lock_user_struct(VERIFY_WRITE, target_stx, arg5,
> 0)) {
> + return -TARGET_EFAULT;
> + }
> + memset(target_stx, 0, sizeof(*target_stx));
It would be clearer to put the following conversion lines into a
separate function like host_to_target_statx().
> + __put_user(host_stx.stx_mask, &target_stx->stx_mask);
> + __put_user(host_stx.stx_blksize,
> &target_stx->stx_blksize);
> + __put_user(host_stx.stx_attributes,
> + &target_stx->stx_attributes);
> + __put_user(host_stx.stx_nlink, &target_stx->stx_nlink);
> + __put_user(host_stx.stx_uid, &target_stx->stx_uid);
> + __put_user(host_stx.stx_gid, &target_stx->stx_gid);
> + __put_user(host_stx.stx_mode, &target_stx->stx_mode);
> + __put_user(host_stx.stx_ino, &target_stx->stx_ino);
> + __put_user(host_stx.stx_size, &target_stx->stx_size);
> + __put_user(host_stx.stx_blocks, &target_stx->stx_blocks);
> + __put_user(host_stx.stx_attributes_mask,
> + &target_stx->stx_attributes_mask);
perhaps you can also define host_target_statx_timestamp() function to
convert the timestamps.
> + __put_user(host_stx.stx_atime.tv_sec,
> + &target_stx->stx_atime.tv_sec);
> + __put_user(host_stx.stx_atime.tv_nsec,
> + &target_stx->stx_atime.tv_nsec);
> + __put_user(host_stx.stx_btime.tv_sec,
> + &target_stx->stx_atime.tv_sec);
> + __put_user(host_stx.stx_btime.tv_nsec,
> + &target_stx->stx_atime.tv_nsec);
> + __put_user(host_stx.stx_ctime.tv_sec,
> + &target_stx->stx_atime.tv_sec);
> + __put_user(host_stx.stx_ctime.tv_nsec,
> + &target_stx->stx_atime.tv_nsec);
> + __put_user(host_stx.stx_mtime.tv_sec,
> + &target_stx->stx_atime.tv_sec);
> + __put_user(host_stx.stx_mtime.tv_nsec,
> + &target_stx->stx_atime.tv_nsec);
> + __put_user(host_stx.stx_rdev_major,
> + &target_stx->stx_rdev_major);
> + __put_user(host_stx.stx_rdev_minor,
> + &target_stx->stx_rdev_minor);
> + __put_user(host_stx.stx_dev_major,
> + &target_stx->stx_dev_major);
> + __put_user(host_stx.stx_dev_minor,
> + &target_stx->stx_dev_minor);
> + }
> +
> + if (ret != TARGET_ENOSYS) {
> + break;
it should be "return ret;"
> + }
> + }
> +#endif
You use p here as it can be unlocked in the last 'if" body".
> + if ((p == NULL) || (*((char *)p) == 0)) {
> + /*
> + * By file descriptor
> + */
if AT_EMPY_PATH is not specified in the flags, you should return -ENOENT
> + ret = get_errno(fstat(dirfd, &st));
> + unlock_user(p, arg2, 0);
> + } else if (*((char *)p) == '/') {
> + /*
> + * By absolute pathname
> + */
> + ret = get_errno(stat(path(p), &st));
> + unlock_user(p, arg2, 0);
> + } else {
> + if (dirfd == AT_FDCWD) {
> + /*
> + * By pathname relative to the current working directory
> + */
> + ret = get_errno(stat(path(p), &st));
> + unlock_user(p, arg2, 0);
> + } else {
> + /*
> + * By pathname relative to the directory referred to by
> + * the file descriptor 'dirfd'
> + */
> + ret = get_errno(fstatat(dirfd, path(p), &st, flags));
> + unlock_user(p, arg2, 0);
> + }
> + }
I think you can put the unlock_user() only once here.
> +
> + if (!is_error(ret)) {
> + if (!lock_user_struct(VERIFY_WRITE, target_stx, arg5, 0)) {
> + return -TARGET_EFAULT;
> + }
> + memset(target_stx, 0, sizeof(*target_stx));
> + __put_user(major(st.st_dev), &target_stx->stx_dev_major);
> + __put_user(minor(st.st_dev), &target_stx->stx_dev_minor);
> + __put_user(st.st_ino, &target_stx->stx_ino);
> + __put_user(st.st_mode, &target_stx->stx_mode);
> + __put_user(st.st_uid, &target_stx->stx_uid);
> + __put_user(st.st_gid, &target_stx->stx_gid);
> + __put_user(st.st_nlink, &target_stx->stx_nlink);
> + __put_user(major(st.st_rdev), &target_stx->stx_rdev_major);
> + __put_user(minor(st.st_rdev), &target_stx->stx_rdev_minor);
> + __put_user(st.st_size, &target_stx->stx_size);
> + __put_user(st.st_blksize, &target_stx->stx_blksize);
> + __put_user(st.st_blocks, &target_stx->stx_blocks);
> + __put_user(st.st_atime, &target_stx->stx_atime.tv_sec);
> + __put_user(st.st_mtime, &target_stx->stx_mtime.tv_sec);
> + __put_user(st.st_ctime, &target_stx->stx_ctime.tv_sec);
> + unlock_user_struct(target_stx, arg5, 1);
> + }
> + }
> + break;
should be "return ret;" now.
> +#endif
> #ifdef TARGET_NR_lchown
> case TARGET_NR_lchown:
> if (!(p = lock_user_string(arg1)))
> diff --git a/linux-user/syscall_defs.h b/linux-user/syscall_defs.h
> index 18d434d..b6c5c4f 100644
> --- a/linux-user/syscall_defs.h
> +++ b/linux-user/syscall_defs.h
> @@ -2488,4 +2488,42 @@ struct target_user_cap_data {
> /* Return size of the log buffer */
> #define TARGET_SYSLOG_ACTION_SIZE_BUFFER 10
>
> +struct target_statx_timestamp {
> + int64_t tv_sec;
> + uint32_t tv_nsec;
> + int32_t __reserved;
> +};
You sould use abi_ullong, abi_uint and abi_int to have the good
alignment in the structure.
> +
> +struct target_statx {
> + /* 0x00 */
> + uint32_t stx_mask; /* What results were written [uncond] */
> + uint32_t stx_blksize; /* Preferred general I/O size [uncond] */
> + uint64_t stx_attributes; /* Flags conveying information about the file */
> + /* 0x10 */
> + uint32_t stx_nlink; /* Number of hard links */
> + uint32_t stx_uid; /* User ID of owner */
> + uint32_t stx_gid; /* Group ID of owner */
> + uint16_t stx_mode; /* File mode */
> + uint16_t __spare0[1];
> + /* 0x20 */
> + uint64_t stx_ino; /* Inode number */
> + uint64_t stx_size; /* File size */
> + uint64_t stx_blocks; /* Number of 512-byte blocks allocated */
> + uint64_t stx_attributes_mask; /* Mask to show what's supported in
> + stx_attributes */
> + /* 0x40 */
> + struct target_statx_timestamp stx_atime; /* Last access time */
> + struct target_statx_timestamp stx_btime; /* File creation time */
> + struct target_statx_timestamp stx_ctime; /* Last attribute change time
> */
> + struct target_statx_timestamp stx_mtime; /* Last data modification time
> */
> + /* 0x80 */
> + uint32_t stx_rdev_major; /* Device ID of special file [if bdev/cdev] */
> + uint32_t stx_rdev_minor;
> + uint32_t stx_dev_major; /* ID of device containing file [uncond] */
> + uint32_t stx_dev_minor;
> + /* 0x90 */
> + uint64_t __spare2[14]; /* Spare space for future expansion */
> + /* 0x100 */
> +};
>
Same here use abi_XXX types.
> #endif
>
Thanks,
Laurent
